The present invention relates generally to an apparatus for opening and closing a car door and a shaft door of an elevator installation, wherein in the case of a stop of an elevator car at a floor, an entraining system couples the car door and the shaft door and a locking device unlocks the doors in the opening process and locks them in the closing process.
Equipment for driving, coupling and locking a car door and a shaft door for elevators is shown in the European patent specification 0 513 509. Upon arriving at a destination floor, a door drive device is switched to an opening mode. Before the sliding door executes a movement, a strip-shaped drive means draws a clamping element along a sliding guide, whereby a control cam, which actuates a pull rod by means of a double lever, is rotated. In that case the pull rod spreads an entraining parallelogram which projects at coupling rollers of the shaft door. The double lever in turn presses up an actuating roller of a car door lock, whereby the car door lock is taken out of the locking position. Then the doors can be opened.
This known equipment has a complicated mechanical construction and consists of individual parts which are expensive to produce, such as a clamping element, a sliding guide, a control cam, rotational axles, a toggle lever, rollers, a double lever, a pull rod, a support roller, a car door lock, an actuating strap, etc., which in matters of cost, manufacture, maintenance, susceptibility to fault and reliability is very disadvantageous. Moreover, it is to be regarded as a disadvantage that before the actual opening process can begin, the door drive must spread the entraining parallelogram and the locking mechanism must actuate the car door, by which a loss of time arises.